Chair frame



FIG. 1 illustrates a front elevation view of a chair frame showing my new design;

FIG. 2 illustrates a rear elevation view thereof;

FIG. 3 illustrates a left side elevation view thereof, the right side elevation view being a mirror image thereof;

FIG. 4 illustrates a top plan view thereof; and,

FIG. 5 illustrates a bottom plan view thereof. 

The ornamental design of a chair frame, as shown and described. 